China: In a recent study published in Acta Obstetricia et Gynecologica Scandinavica, the researchers found no association between caffeine consumption and pregnancy or live birth rate of fertility treatments in women (in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI)).
The study further revealed that women's alcohol consumption was linked with decreased pregnancy rate after treatments in cases where weekly consumption was greater than 84 g (approximately 7 standard drinks).

Also, men's alcohol consumption was associated with a decreased live birth rate after fertility treatments in women when weekly consumption was greater than 84 g.
The analysis included all relevant studies published before July 15, 2022. A total of 7 studies on caffeine consumption and 9 studies on alcohol consumption were included, with a total of 26,922 women and/or their spouses who underwent fertility treatment.
Compared with abstainers, the chance of achieving a pregnancy after fertility treatment decreased by 7% for women who consumed 84 g of alcohol per week, and the chance of partners achieving a live birth decreased by 9% for men who consumed 84 g of alcohol per week.
The study led to the following findings:
The systematic review included twelve studies on caffeine consumption and 14 studies on alcohol consumption, of which seven and nine were eligible for the meta-analysis. These studies included 26 922 women and/or their spouses who underwent IVF/ICSI treatment.
Women's and men's caffeine consumption was not significantly associated with the pregnancy rate and the live birth rate of IVF/ICSI.
Maternal alcohol consumption was negatively associated with pregnancy after IVF/ICSI treatment.
Paternal alcohol consumption was negatively associated with partner's live birth after IVF/ICSI treatment.
Compared with abstainers, the chance of achieving a pregnancy after IVF/ICSI treatment decreased by 7% for women who consumed 84 g alcohol per week, and the chance of partners achieving a live birth decreased by 9% for men who consumed 84 g alcohol per week.

"Couples should be aware that some modifiable lifestyle factors such as drinking habits may affect their fertility treatment outcomes. But how these factors impact the reproductive system still needs more research to elucidate," said corresponding author Yufeng Li, MD, of Tongji Hospital, in China.
Reference:
Wentao Rao,Yuying Li,Nijie Li,Qingyun Yao,Yufeng Li First published: 19 October 2022 https://doi.org/10.1111/aogs.14464